Clamp



p 0, 1969 J. A. FARRINGTON, JR. ETAL 3,

CLAMP 2 Sheets-Sheet 1 Filed Dec. 9, 1966 Sept. 30, 1969 J. A. FARRINGTQN, JR., ETAL CLAMP 2 Sheets-Sheet Filed Dec. 9, 1966 United States Patent 3,470,528 CLAMP John A. Farrington, Jr., Birmingham, Gordon L. Flynn, Trussville, and Stancel D. Phillips and John V. Scott, Birmingham, Ala., assignors to Anderson Electric Corporation, Leeds, Ala., a corporation of Alabama Filed Dec. 9, 1966, Ser. No. 600,516 Int. Cl. H01r 7/26, 7/18 US. Cl. 339-265 7 Claims ABSTRACT OF THE DISCLOSURE A clamp for an electrical conductor having a first jaw with a conductor receiving groove in one face thereof and a pair of holes on one side of the groove spaced along the length of the groove. A hole and a laterally opening notch are provided on the other side of the groove and spaced along the length thereof. A first U-bolt has its legs slidably received in said pair of holes while a second U-bolt has one of its legs slidably received in the hole on said other side of the groove and its other leg receivable in the notch. A second jaw is attached at one side thereof to the second bolt. This bolt is swingable about the axis of its said one leg between a clamping position wherein the second jaw lies opposite the first jaw and a retracted position clear of the first jaw.

Among the several objects of the invention may be noted the provision of a conductor clamp which is particularly suitable for hot line application; the provision of a clamp which is easily opened to remove or insert a conductor; the provision of an easily openable clamp wherein U-bolts which are raised to open the clamp will remain in the raised position until intentionally returned to the lowered position; the provision of a clamp for electrical conductors wherein the clamp opens in such a manner that a conductor can be received intoand removed from the clamp without threading the conductor through the clamp, and to such a clamp wherein the parts remain attached to each other when the clamp is opened, thereby making the clamp very suitable for hot line uses and avoiding loss of parts of the clamp; and the provision of a conductor clamp wherein the parts are arranged to permit a comparatively high clamping force to be applied to the conductor. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of the various possible embodiments of the invention is illustrated,

FIG. 1 is a plan of a clamp of the invention applied to an electrically conductive cable;

FIG. 2 is a side elevation of the FIG. 1 clamp;

FIG. 3 is a fragmentary plan showing the clamp with one jaw swung away from the FIG. 1 position so that a cable can be placed into or removed from the clamp; and

FIG. 4 is a view taken from the left end of FIG. 3.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, a clamp of the invention comprises a lower jaw 1 having in its upper face an elongate groove 3 which is substantially straight from one end to the other end. Groove 3 is shaped so that it receives the underside of an electrical conductor such as the multistrand cable 5 shown in FIGS. 1 and 2. Groove 3 is open at the top and ends as shown in FIGS. 3 and 4.

A pair of holes 7 and 9 at one side of groove 3 are spaced from each other along the length of the groove. At the side of the groove 3 opposite holes 7 and 9 there is a hole 11 and a notch 13. The notch opens laterally of jaw 1 as shown in FIGS. 1 and 3. Hole 11 and notch 13 are spaced along the length of the jaw 1 and groove 3. Hole 11 is transversely aligned with hole 9, and notch 13 is transversely aligned with hole 7 in jaw 1. As shown in FIG. 2, holes 7 and 9 are preferably generally conical in shape being larger at the upper end than at the lower end.

A U-bolt generally designated 15 has a pair of substantially parallel threaded legs 17 and 19 joined at the upper end by a curved bight portion 21. Legs 17 and 19 are received in holes 7 and 9, respectively, and the bight portion lies over the upper face of clamp jaw 1. Nuts 23 and the washers 25 at the lower face of jaw 1 are provided on the threaded end portions 17 and 19 of the U-bolts for fixing the bolts on the jaw. When nuts 23 are tightened the bight portion 21 of the bolt is drawn down toward the jaw to the FIG. 2 position and when the nuts are loosened the bight portion can be raised relative to the jaw 1 as shown in FIGS. 3 and 4. Because the holes 7 and 9 are somewhat larger at the upper end than at the lower end, the bolt can be tilted or inclined relative to the axes of the holes as shown in FIGS. 3 and 4.

Preferably, one or both of the holes 7 and 9 are at least partially lined with a material or substance designated 27 (FIG. 2) which constitutes means frictionally engaging the legs of the bolt so that the bolt legs tend to remain in either the lowered or elevated position until they are intentionally moved to the other position. Substance 27 may be a silicone rubber material manufactured by the Dow Corning Co. of Midland, Michigan, and sold under the trade designation Silastic.

A pair of clevis legs 29 and 31 project rearwardly from jaw 1 at opposite sides of groove 3. Legs 29 and 31 are spaced from each other and are generally parallel to each other. The spacing between the outer ends of the legs is maintained uniform by a bar 33 extending between and joined to the legs at the end portion thereof opposite from the groove 3. Legs 29 and 31 have aligned holes 35 and 37 therethrough which are adapted to receive a pin for connecting the clamp jaw 1 to a suitable insulator (not shown). The clevis legs are preferably relatively narrow which is desirable if a pigtail is to be formed at the end of the conductor since this permits easy access to the conductor 5 for forming the pigtail. It will be understood that the conductor 5 can be turned either upwardly as shown in solid lines in FIG. 2 or downwardly as shown in dotted lines at FIG. 2 and in either case the end of the conductor clears the spacer bar 33. The substantially flat surface on bar 33 nearest holes 35, 37 is adapted to bear against a substantially flat squared ofi surface of an insulator eye to prevent any significant swinging movement of the clamp relative to the insulator. At the end of the jaw opposite from the clevis legs 29 and 31 there is a pulling eye 39 which is adapted, for example, to receive a hook on a hoist used for tensioning the cable prior to clamping.

A second U-bolt 41 has 'a pair of spaced threaded legs 43 and 45 which are joined by a bight portion 47. Leg 43 of bolt 41 is received in the hole 11 of jaw 1 and leg 45 is adapted to be positioned in notch 13.

A material such as shown at 27 is also preferably provided as at least a partial lining in hole 11 for frictional engagement of bolt leg 43 to prevent inadvertent raising or lowering of bolt 41. Nuts 46 and Washers 48 receive the lower end of legs 43 and 45.

A second clamp jaw 49 is attached to or held captive on the second bolt 41 by a pair of fingers 51 which project upwardly from the top face of jaw 49 and are peened over the bight portion 47 of the bolt 41, thus maintaining or sustaining jaw fixed on U-bolt 41 in a position extending laterally or perpendicularly with respect to the plane of U-bolt 41 and on one side of the plane thereof. Jaw 49 has a length greater than the width or span of U-bolt 41 and an elongate straight groove 53 extending along its lower face from one end of the jaw to the other end thereof for receiving the upper surface of cable 5. Groove 53 faces the groove 3 in jaw 1 when jaw 49 is in the clamping position shown in FIGS. 1 and 2.

A laterally projecting tongue 55 at the center portion of the jaw 49 is adapted to be received within the bight portion 21 of U-bolt 15 when the second jaw is in the clamping position. Tongue 55 has a generally U-shape groove 57 on its upper face which receives the lower surface of the bight portion 21 of bolt 15 so that when nuts 23 and 46 are tightened the jaw 49 is pulled down against the upper part of cable 5. Groove 57 is on the opposite side of the cable groove 53 from the U-bolt 41.

An eye 61 is provided at the top of jaw 49. A suitable linemans tool, such as a hot-stick, can be placed in eye 61 for lifting and turning the upper jaw when a cable is being placed into or removed from the clamp.

In one exemplary way of utilizing the clamp of this invention it is attached to the end of a cable or the like by first attaching the clevis end of the clamp to an insulator eye and engaging the hook of a hoist, or ratchet type take-up device, in eye 39. The hoist is also attached to cable 5. The cable is tensioned by operation of the hoist. Then the clamp is opened to the position shown in FIGS. 3 and 4. To raise tongue 55 of upper jaw 49 without interference from the bight portion 21 of U- bolt 15, the nuts 23 and 46 are first loosened to permit vertical movement of the U-bolt. It is then lifted either vertically a sufiicient distance to permit the raising and swinging of jaw 49 to its FIG. 3 position or bolt is lifted vertically a lesser distance and then tilted sideways as shown in FIG. 4 to permit the lifting and swinging of jaw 49. Upward movement of jaw 49 is accomplished by lifting the U-bolt 41 attached to the jaw. Then U-bolt 41 is swung about the axis of leg 43 to move leg 45 of the bolt out of notch 13 and into the position shown in FIGS. 3 and 4. This movement carries jaw 49 from the clamping position shown in FIG. 1 to a position at the side of groove 3 and jaw 1 rearward of bolt leg 43 wherein the jaw 1 is completely open to receive cable 5, such being desirable since it is almost impossible to thread a substantially inflexible cable through an eye in a clamp. U-bolt 15 remains in the position shown in FIGS. 3 and 4 due to the frictional engagement between the legs of the bolt and the substance 27 lining holes 9 and 11.

Then cable 5 is placed in groove 3 and jaw 49 is swung about the axis of bolt leg 43 from the FIG. 3 position to a position wherein bolt leg 45 is in notch 13, and groove 53 in jaw 49 overlies the upper portion of the cable 5. If U-bolt 15 is tilted it is moved from the tilted position shown in FIG. 4 to an upright position wherein its bight portion 21 straddles the groove 57 in tongue 55 of jaw 49. The nuts 23 and 46 then are tightened against the lower face of jaw 41 to draw the bights 21 and 47 of the U-bolts downwardly, thereby pulling the jaw 49 tightly against the upper surface of the cable 5. The nuts are tightened until the cable is securely gripped by the clamp. Then the hoist is removed from the cable and the clamp. The clamp is released from the cable by loosening nuts 23 and 46, tilting the bolt 15 to its FIG. 4 position, and then raising and swinging the jaw 49 from above the cable 5 to the open position shown in FIGS. 3 and 4.

The ease with which the clamp is attached to and removed from a cable makes it particularly suitable for hot line installations. Structural features which facilitate opening and closing of the clamp include the lifting eye 61, the attachment of the upper jaw 49 to the U-bolt 41 and the use of substance 27 which holds the U-bolt in either the raised or lowered position until it is intentionally returned to the other position. Also, the location of the U-bolts along the sides of the cable grooves (instead of straddling the cable grooves) permits attachment of the clamp to the cable without threading the conductor through the clamp. Because the clamp parts are attached to each other even when the clamp is open, loss of parts of the clamp is avoided.

It has been found that by clamping the cable between two U-bolts positioned generally parallel to the length of the cable a greater clamping force can be applied to the conductor 5 than can be obtained with clamps wherein the U-bolts straddle the cable. While grooves 3 and 53 are shown as being straight throughout their lengths, it will be understood that the grooves may be shaped with cooperating recesses and projecting for further increasing the pressure of the clamp against the cable. While the preceding description has referred to cable 5 as being an electrical conductor, it will be understood that the clamp is useful for clamping cables which are not current carrying members.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A clamp for connection to an electrical conductor comprising:

a first jaw having a groove in one face thereof for receiving the conductor,

said first jaw having a pair of holes on one side of said groove spaced along the length of the groove and a hole and a laterally opening notch on the opposite side of said groove spaced along the length of the groove, a first U-bolt having its legs slidably entered in said pair of holes on said one side of said groove from said one face of said first jaw and having nuts threaded on its legs on the opposite face of said first jaw,

a second U-bolt having one leg slidably entered in the hole on the said other side of the groove from said one face of said first jaw and its other leg receivable in said notch,

and a second jaw attached at one side thereof to the second bolt,

said second bolt being swingable about the axis of its said one leg between a clamping position wherein said second jaw lies opposite said first jaw and a retracted position clear of said first jaw,

said second jaw being adapted to sustain a position extending laterally with respect to the plane of the second bolt on one side of said plane when the second bolt is in retracted position,

said second jaw having a groove facing the groove in the first jaw when the second jaw is in its clamping position and also having a tongue projecting laterally from its opposite side which is received in the bight of the first U-bolt when the second jaw is in its clamping position.

2. A clamp as set forth in claim 1 wherein said pair of holes at said one side of the groove in the first jaw are each larger at one end than at the other end whereby the first bolt can be tilted away from the second bolt when the nuts are loosened.

3. A clamp as set forth in claim 1 wherein one hole of said pair of holes and the hole at said other side of the groove in the first jaw each includes means frictionally engaging the bolts whereby the bolts tend to remain in an adjusted position in the holes.

4. A clamp as set forth in claim 1 wherein the grooves in said jaws are substantially straight from one end to the other end of the grooves.

5. A clamp as set forth in claim 1 further comprising a pair of spaced and generally parallel legs projecting from one of the clamp jaws at opposite sides of the groove therein, the outer ends of said legs having aligned holes therethrough adapted to receive a pin for connecting the legs to an insulator, and a spacer member extending between the legs near the holes therethrough for holding the legs a fixed distance apart.

6. A clamp as set forth in claim 1 further comprising an eye on said second jaw adapted to receive a tool for swinging the second jaw about said one leg of the second bolt.

7. A clamp as set forth in claim 1 wherein the second jaw has a length greater than the span of the second U-bolt and is fixed thereto to extend perpendicularly therefrom.

References Cited UNITED STATES PATENTS 11/1956 Vordtriede 339265 X 4/ 1957 Sorflaten et a1. 339--265 7/1960 Bethea 339265 X 8/1960 Toedtman 339265 9/1961 Kraase et al. 339-265 5/1962 Bethea 339265 FOREIGN PATENTS 6/ 1965 France.

OTHER REFERENCES Electric World: July 7, 1958, page 89, Burndy clamp.

MARION A. CHAMPION, Primary Examiner P. A. CLIFFORD, Assistant Examiner U.S. Cl. X.R. 

